The manner in which light (e.g., visible, near-ultraviolet, and near-infrared electromagnetic radiation) interacts with matter provides important information about the composition of the matter. Information on chemical substances, for example, can be determined from their specific absorption or emission of light. Thus, certain analytical procedures include an analysis of the amount of light absorbed or transmitted as that light passes through a sample. In that context, spectrophotometry is the quantitative measurement of the reflection and transmission of light through/from matter as a function of wavelength. Spectrophotometry is a more particular term than electromagnetic spectroscopy in that spectrophotometry deals with visible light, near-ultraviolet, and near-infrared, but generally does not include time-resolved spectroscopic techniques.
Spectrophotometers are relied upon across various technical and scientific fields, such as physics, materials science, chemistry, biology, and biochemistry. Spectrophotometers are also used in various industries including the semiconductor, laser manufacturing, optical manufacturing, printing, and forensic examination industries. When properly calibrated, a spectrophotometer can be used to determine what substances are present in a composition under test through the observed wavelengths of transmittance or reflectance, converted to absorbance for quantitative measurements.
The drawings illustrate only example embodiments and are therefore not to be considered limiting of the scope of the embodiments described herein, as other embodiments are within the scope of this disclosure. The elements and features shown in the drawings are not necessarily drawn to scale, emphasis instead being placed upon clearly illustrating the principles of the embodiments. Additionally, certain dimensions or positionings may be exaggerated to help visually convey certain principles. In the drawings, similar reference numerals between figures designate like or corresponding, but not necessarily the same, elements.